FRESNO, Calif. — Three people presumed dead after being swept over a raging waterfall in Yosemite National Park ignored warning signs and crossed a barricade to pose for photographs, a witness said Wednesday.

Other hikers on the trail above the 317-foot Vernal Falls warned the group that conditions in the Merced River were treacherous.

“People come up here and they think it’s Disneyland,” said Jake Bibee, 28, who says he is haunted by the look of terror in one man’s eyes as he was swept over the falls clinging to his female companion.

The Yosemite Search and Rescue unit identified the victims as Homiz David, 22, of Modesto; Ninos Yacoub, 27, of Turlock; and Ramina Badal, 21, of Modesto.